Date of Award


Level of Access Assigned by Author

Open-Access Dissertation

Degree Name

Doctor of Philosophy (PhD)


Ecology and Environmental Sciences


Stewart N. Smith

Second Committee Member

Gregory A. Porter

Third Committee Member

Timothy J. Dalton


This thesis examines the profitability of and sustainability indicators for potato and dairy farms in Maine integrating crops and livestock in two different ways. The first is inter-farm coupling, where two or more specialized producers are close enough to exchange manure applications for crops used as livestock feed. Land base is shared between farmers. The second is where farms are on-farm integrated. Here crops and livestock are raised on the same farm and manure is applied to cash crops and livestock feed crops. Face-to-face interviews with Maine producers were used to construct integrated and non-integrated representative budgets. Assuming potato farms expanded and dairy farms did not, net farm income for central Maine and Aroostook County coupled potato and dairy agricultural systems compared to non-integrated systems improved from increased potato acreage in the short term ($46/acre), and manure nutrient credits ($36/acre) and a 5% increase in potato yields ($75/acre) assumed in the long term. Use of the dairy farm's cultivated acreage during coupling allowed potato farms to expand potato acreage. Short-term coupled potato farms were able to grow more potatoes, a more profitable cash crop while keeping the same rotation sequence. Profitability improved for dairy farms if forage acreage and herd size could be expanded from coupling. Coupled dairy farms that relocated to Aroostook County had increased profitability due to lower land ownership and rental costs. On-farm integrated dairy farms growing concentrated livestock feed crops were more profitable than conventional dairy farms in both central Maine and Aroostook County. Growing and processing concentrated feed crops was cheaper than buying such feed at typical market prices assuming land was available to grow these crops. Sustainability indicators also improved for coupled and on-farm integrated systems compared to conventional systems. Both integration types are not prevalent in Maine despite short- and long-term economic benefits. Challenges to adopting integrated crop and livestock systems include distance between potential couplers, establishing and maintaining successful coupled relationships, management of inter-farm coupling and other crops, land availability, and the terms of processing potato contracts. Integration in Aroostook County is also challenged by a lack of infrastructure for dairy farms.

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